Support MycoNote →

MycoNote

Oyster mushroom or Poplar fieldcap

How they differ, how to recognize them and which is more dangerous — a mushroom comparison

The short answer

Oyster mushroom and Poplar fieldcap are similar species that can be mixed up while foraging. The main visible difference: season: Oyster mushroom — spring, autumn, winter, Poplar fieldcap — spring, summer, autumn. The mushrooms also differ in the following features: use, cap color, cap shape.

Oyster mushrooms (Pleurotus ostreatus)

Oyster mushroom

Pleurotus ostreatus

EdibleExpert-verified
Poplar fieldcap (Cyclocybe aegerita)

Poplar fieldcap

Cyclocybe aegerita

EdibleNot reviewed by an editor

📊 Comparing characteristics

Comparison of characteristics: Oyster mushroom and Poplar fieldcap
Edibility class

Oyster mushroom

Edible

Poplar fieldcap

Edible
Season

Oyster mushroom

SpringAutumnWinter

Poplar fieldcap

SpringSummerAutumn
Use

Oyster mushroom

CulinaryCook freshFreezing

Poplar fieldcap

Cook freshDrying
Size

Oyster mushroom

Medium (5–15 cm)

Poplar fieldcap

Medium (5–15 cm)
Cap color

Oyster mushroom

GreyDark greyBrown

Poplar fieldcap

BrownCreamWhite
Cap shape

Oyster mushroom

Irregular

Poplar fieldcap

ConvexFlat
Cap surface

Oyster mushroom

Smooth

Poplar fieldcap

SmoothCracked
Taste

Oyster mushroom

Mild

Poplar fieldcap

Mild
Smell

Oyster mushroom

Pleasant, mushroomy

Poplar fieldcap

Pleasant
Flesh color change

Oyster mushroom

No change

Poplar fieldcap

No change
Hymenophore

Oyster mushroom

Gilled

Poplar fieldcap

Gilled
Stem

Oyster mushroom

LateralEccentric

Poplar fieldcap

Central
Ring (veil)

Oyster mushroom

No ring

Poplar fieldcap

Ring present
Volva

Oyster mushroom

No volva

Poplar fieldcap

No volva
Substrate

Oyster mushroom

Dead woodOn wood

Poplar fieldcap

Dead woodLiving tree
Nutrition type

Oyster mushroom

Saprotroph

Poplar fieldcap

Saprotroph
Partner trees

Oyster mushroom

PoplarWillowBeechAspen

Poplar fieldcap

Aspen

📅 Seasonality

Oyster mushroom

Fruiting season

Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

January, February, March, September, October, November, December

Poplar fieldcap

Fruiting season

Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

April – October

🔬 Morphology

Cap

Oyster mushroom

Cap 5–25 cm across, rounded or ear-shaped in young mushrooms, then fan-shaped or oyster-shaped (hence the English name oyster mushroom). Surface smooth, moist, from dark gray or gray-blue in young ones to pale gray or almost white in mature ones. Margin wavy, thin.

Poplar fieldcap

The cap of the poplar fieldcap is 4 to 10, occasionally up to 15 centimeters across. When young it is hemispherical; with age it opens to convex and flat, often with fine radial cracks across the surface in dry weather. The surface is smooth, dry and matte. The color is dark brown or chestnut at first, fading with age and from center to edge to light ochre, cream or nearly white; the center is usually darker.

Hymenophore

Oyster mushroom

Gills crowded, whitish or cream, running from the cap down the stem. In young mushrooms the gills are tightly packed; in old ones they spread apart. Spore print white or pale lilac.

Poplar fieldcap

The spore-bearing surface is made of gills. The gills are attached to the stem and fairly crowded, whitish or pale gray at first, turning tobacco-brown, rusty-brown from the spores as they mature. The spore print is tobacco-brown. Pale gills that brown with age, together with the ring on the stem, help you recognize this species.

Stem

Oyster mushroom

Stem 1–5 cm tall (or almost absent in side-attached mushrooms), 1–2.5 cm thick, firm, off-center or lateral, white or slightly gray. No ring and no volva.

Poplar fieldcap

The stem is cylindrical, fairly long and firm, 5 to 12 centimeters tall, white or cream, often browning toward the base. Near the top there is a persistent white membranous ring — a remnant of the veil — on which brown spore dust often settles. Several stems fuse together in a cluster at the base. There is no volva. The stem flesh is tougher than the cap, so mostly the caps are eaten.

Flesh

Oyster mushroom

Flesh white, firm in young mushrooms, more fibrous and tough in mature ones — especially in the stem. Taste mild, slightly anise-like. Soaks up flavors well during cooking.

Poplar fieldcap

The flesh is white, firm and springy — fleshy in the cap and fibrous-tough in the stem. It does not change color when cut. The taste is pleasant, nutty and mushroomy, sometimes with a light winey note. Thanks to its firmness, the flesh holds its shape when cooked and doesn't turn mushy, which is why the mushroom is so valued in the kitchen.

Smell

Oyster mushroom

Smell pleasant, anise-mushroomy, subtle. Fresh oyster mushrooms smell soft and unobtrusive. When fried, the aroma becomes stronger and closer to the classic mushroom smell.

Poplar fieldcap

The smell is pleasant and mushroomy, with a distinctive winey-mealy or cedar-like note. The aroma is quite pronounced and helps you recognize the mushroom, along with its clustered growth on poplar, pale cap and white ring on the stem.

📍 Habitats

Oyster mushroom

Deciduous forestMixed forest

Poplar fieldcap

Deciduous forestMixed forest

👀 Similar mushrooms — don't mix them up!

❓ Frequently asked questions

Can Oyster mushroom and Poplar fieldcap be mixed up?
Yes, they look so similar that people often mix them up. The season, use, cap color help tell them apart.
How to tell Oyster mushroom from Poplar fieldcap?
The main differences: season: Oyster mushroom — spring, autumn, winter, Poplar fieldcap — spring, summer, autumn; use: Oyster mushroom — culinary, cook fresh, freezing, Poplar fieldcap — cook fresh, drying; cap color: Oyster mushroom — grey, dark grey, brown, Poplar fieldcap — brown, cream, white. The full table of characteristics is higher up on this page.
Is Poplar fieldcap edible?
Poplar fieldcap — edible.
When do Oyster mushroom and Poplar fieldcap grow?
Oyster mushroom — January–December; Poplar fieldcap — April–October.

Sources

  • [1]Атлас грибів України, Зеров Д.К. (1979)
  • [2]GBIF
  • [3]Вікіпедія (українська)
  • [4]MycoBank Database
  • [5]Index Fungorum
  • [6]iNaturalist Ukraine